How do I decompose a number into powers of 2?

Question

I\'m trying to create a function that receives a number as an argument and performs actions on that number to find out its closest powers of 2 that will then add up to that

Answer 1

The idea is to convert the number to binary and then get powers of two from the binary representation:

#!/usr/bin/env python


def get_powers(n):
    """Get positive powers of two which add up to n.

    Parameters
    ----------
    n : positive integer

    Returns
    -------
    list of integers which are powers of 2

    Examples
    --------
    >>> get_powers(14)
    [2, 4, 8]

    >>> get_powers(5)
    [1, 4]
    """
    get_bin = lambda x: x >= 0 and str(bin(x))[2:] or "-" + str(bin(x))[3:]
    bin_str = get_bin(n)  # convert n to a binary string
    powers = []
    for i, digit in enumerate(bin_str[::-1]):
        if digit == '1':
            powers.append(2**i)
    return powers